离子诱导固定空间取向下的双原子分子碎裂动力学研究

项目名称： 离子诱导固定空间取向下的双原子分子碎裂动力学研究

项目编号： No.U1332128

项目类型： 联合基金项目

立项/批准年度： 2014

项目学科： 数理科学和化学

项目作者： 李斌

作者单位： 中国科学院近代物理研究所

项目金额： 76万元

中文摘要： 离子分子碰撞过程涉及的问题基础而广泛，长期以来始终是分子物理学中一个活跃的研究领域。反应谱仪的发展为精细测量研究碰撞碎裂动力学过程提供了新的契机。本项目拟基于兰州重离子加速器实验装置，采用先进的动量成像技术，以CO和NO为例实验研究离子诱导双原子分子碎裂动力学。通过对碎片离子动量矢量测量，获得碎裂反应高精度动能释放量，判断碎裂过程的分子态选择性；获得碎片离子角分布，还原碎裂前分子空间取向，进而考察KER对取向的依赖关系及碎裂模式和碎裂机制在不同分子轴取向下的异同；再通过符合测量电离电子动量矢量，获得转移电离过程全微分截面，研究分子固定空间取向下电离电子的角分布，通过重构出射电子和碎片离子的能量关联谱，考察沉积于分子中的额外剩余能量在各碎裂产物中的分配机制。

中文关键词： 取向效应；电离解离；反应显微成像谱仪；重离子；动能释放

英文摘要： The ion induced fragmentation of small molecules has been an active area in molecular physics for a long time. The development of reaction spectroscopy offers an opportunity to unravel the fragmentation dynamics in unprecedented detail. In this project, based on the Heavy Ion Research Facility in Lanzhou, as prototype of diatomic molecules, the fragmentation dynamics of CO and NO will be investigated by using the momentum imaging technique. The Kinetic Energy Release (KER) in the fragmentation process and the angular distributions of the fragments will be extracted from the measured fragment momentum vectors with high precision. The molecular state selectivity of the fragmentation will be obtained in comparison the measured KERs with reported theoretical results. The initial relative orientation between the molecule inter-nuclear axis and the projectile direction will be calculated from the fragment ion momentum spectroscopy. Then the orientation dependence of the KER and the fragmentation pattern will be studied. In the case of transfer ionization, in conjunction with electron spectroscopy imaging, a detailed study of electron emission in the molecular frame will be performed. From the energy correlation spectrum of the emitted electron and fragment ions, the excitation energy partitioning among the emitted pro

英文关键词： Orientation effect；Dissociative ionization；Reaction microscope；Heavy ion；KER